TW201715093A - Method for manufacturing metal-filled microstructure - Google Patents

Abstract

The present invention addresses the problem of providing a method for manufacturing a metal-filled microstructure device with which the filling of metal into micropores is easy and in-plane uniformity is also good. This method for manufacturing a metal-filled microstructure device comprises: an anodic oxidation step for performing anodic oxidation on one surface of an aluminum substrate to form, on the one surface of the aluminum substrate, an anodic oxide film with micropores that are present in the thickness direction and barrier layers that are present in the bottoms of said micropores; a barrier layer-removing step after the anodic oxidation step for removing the barrier layers of said anodic oxide film using an aqueous alkaline solution comprising a metal M1 with a higher hydrogen overvoltage than aluminum; a metal-filling step after said barrier layer-removing step for performing electroplating to fill a metal M2 inside said micropores; and a substrate-removing step after said metal-filling step for removing the aluminum substrate to obtain the metal-filled microstructure device.

Description

Method for manufacturing metal-filled microstructure

The present invention relates to a method of producing a metal-filled microstructure.

A metal-filled fine structure (device) in which a metal is filled in a fine hole provided in an insulating substrate is one of the fields that has recently attracted attention in nanotechnology, and for example, it is expected to be an anisotropic field. The use of conductive members. The isotropic conductive member is inserted between an electronic component such as a semiconductor element and a circuit board, and is electrically connected only to the circuit board by pressurization. Therefore, it is widely used as an electronic component such as a semiconductor element. An electrical connection member or a connector for inspection when performing a function check.

Patent Document 1 discloses a method for producing a metal-filled microstructure, which includes the following steps: an anodizing treatment step of performing anodization on a surface of one side of an aluminum substrate. An anodic oxide film having a micropore present in a thickness direction and a barrier layer present at a bottom of the micropore; and a barrier layer removing step are formed on a surface of one side of the aluminum substrate After the anodizing treatment step, the barrier layer of the anodized film is removed; a metal filling step, after the barrier layer removing step, performing an electrolytic plating treatment on the microporous layer An internal filling metal; and a substrate removing step of removing the aluminum substrate after the metal filling step to obtain a metal-filled microstructure." (Request 1). [Prior Art Document] [Patent Literature]

[Patent Document 1] International Publication No. 2015/029881

[Problems to be Solved by the Invention] The inventors of the present invention have studied the method for producing a metal-filled microstructure according to Patent Document 1. As a result, it has been found that there is a problem that the metal filling step after the barrier layer removing step In the case where the conditions of the electrolytic plating treatment are different, the filling of the metal into the micropores may be insufficient, and the problem of the micropores not filled with the metal may remain, that is, the in-plane uniformity of the metal filling is poor.

Therefore, an object of the present invention is to provide a method for producing a metal-filled microstructure which is easy to fill a metal in a micropore and which has improved in-plane uniformity. [Means to solve the problem]

The inventors of the present invention conducted intensive studies to achieve the above problems, and as a result, found that a barrier in an anodized film formed by anodizing treatment by using an aqueous alkali solution containing a metal having a hydrogen overvoltage higher than aluminum The layer is removed, and the metal filling into the micropores in the subsequent metal filling step becomes easy, and the in-plane uniformity also becomes good, thereby completing the present invention. That is, the present invention provides a method for producing a metal-filled microstructure having the following structure.

[1] A method for producing a metal-filled microstructure, comprising the steps of: an anodizing treatment step of anodizing a surface of one side of an aluminum substrate to form an anodized film on a surface of one side of the aluminum substrate; Wherein the anodized film has micropores present in a thickness direction and a barrier layer present at a bottom of the micropores; a barrier layer removing step, after the anodizing treatment step, using a hydrogen overvoltage An alkali aqueous solution of the metal M1 higher than aluminum removes the barrier layer of the anodized film; a metal filling step, after the barrier layer removing step, performing an electrolytic plating treatment on the inside of the microporous layer Filling the metal M2; and a substrate removing step, after the metal filling step, removing the aluminum substrate to obtain a metal-filled microstructure. [2] The method for producing a metal-filled microstructure according to [1], wherein the metal M1 used in the barrier layer removing step has a higher ionization tendency than that used in the metal filling step Metal of metal M2. [3] The method for producing a metal-filled microstructure according to [1] or [2], wherein after the metal filling step and before the substrate removing step, a surface metal protruding step is included, the anode is The surface of the oxide film on the side where the aluminum substrate is not provided is partially removed in the thickness direction, so that the metal M2 filled in the metal filling step is more prominent than the surface of the anodized film. [4] The method for producing a metal-filled microstructure according to any one of [1] to [3] wherein, after the substrate removing step, a back metal protruding step is included, and the anodized film is provided The surface on the side of the aluminum substrate is partially removed in the thickness direction, so that the metal M2 filled in the metal filling step is more prominent than the surface of the anodized film. [5] The method for producing a metal-filled microstructure according to [3] or [4], wherein at least one step of the surface metal protruding step and the back metal protruding step is to make the metal M2 The surface of the anodized film protrudes from 10 nm to 1000 nm. [6] The method for producing a metal-filled microstructure according to any one of [1] to [5] wherein after the metal filling step and before the substrate removing step, a resin layer forming step is included A resin layer is provided on a surface of the anodized film on the side where the aluminum substrate is not provided. [7] The method for producing a metal-filled microstructure according to [6], wherein the resin layer is a peelable adhesive layer-attached film. [8] The method for producing a metal-filled microstructure according to [6], wherein the resin layer is adhesively weakened by heat treatment or ultraviolet exposure treatment, and is detachable. The film of the layer. [9] The method for producing a metal-filled microstructure according to any one of [6] to [8] wherein the anodized film formed by the anodizing treatment step has an average thickness of 30 μm or less. [10] The method for producing a metal-filled microstructure according to any one of [6] to [9] wherein after the substrate removing step, the winding step is included, and the metal is filled with the fine structure to have a The state of the resin layer is taken up in a roll shape. [Effects of the Invention]

According to the present invention, it is possible to provide a method for producing a metal-filled fine structure which is easy to fill metal in the micropores and which has improved in-plane uniformity.

[Manufacturing Method of Metal-filled Fine Structure] The method for producing a metal-filled microstructure according to the present invention (hereinafter also simply referred to as "the method for producing the present invention") is a method for producing a metal-filled microstructure including the following steps: anodizing In the treatment step, an anodizing treatment is performed on a surface of one side of the aluminum substrate (hereinafter also referred to as "single side"), and an anodized film is formed on a surface of one side of the aluminum substrate, and the anodized film is present in the thickness a microporous in a direction and a barrier layer present at a bottom of the micropore; a barrier layer removing step, after the anodizing treatment step, using an aqueous alkali solution containing a metal M1 having a hydrogen overvoltage higher than aluminum The barrier layer removal process of the anodized film; the metal filling step, after the barrier layer removing step, performing an electrolytic plating process to fill the inside of the micropore with the metal M2; and a substrate removing step, After the metal filling step, the aluminum substrate is removed to obtain a metal-filled microstructure.

In the present invention, as described above, the barrier layer in the anodized film formed by the anodizing treatment is removed using an aqueous alkali solution containing a metal having a hydrogen overvoltage higher than aluminum, whereby the metal filling step thereafter The filling of the metal into the micropores becomes easy, and the in-plane uniformity also becomes good. Although the details are not clear, they are roughly estimated as follows. First, the reason why the in-plane uniformity is poor is studied in the production method described in Patent Document 1 (International Publication No. 2015/029881). As a result, an acidic plating solution (for example, a copper sulfate aqueous solution or the like) is used in the electrolytic plating treatment. Then, the generation of hydrogen gas is observed at the bottom of the micropores from which the barrier layer is removed, that is, the surface of the exposed aluminum substrate, and the inventors have found that the reason is that the hydrogen gas is temporarily generated, and thereafter The plating solution is difficult to penetrate into the inside of the micropores. On the other hand, in the manufacturing method of the present invention, it is considered that the barrier layer is removed using an aqueous alkali solution containing the metal M1 having a hydrogen overvoltage higher than aluminum before the metal filling step, thereby not only removing the barrier layer but also removing the barrier layer. A metal layer of the metal M1 which is less likely to generate hydrogen gas than aluminum is formed on the aluminum substrate exposed at the bottom of the micropores, and as a result, generation of hydrogen gas by the plating solution is suppressed, and electrolytic plating is easily performed. Metal filling.

Then, the outline of each step in the production method of the present invention will be described with reference to FIGS. 1A to 1E, FIGS. 2A to 2G, and FIGS. 3A to 3F, and then the aluminum substrate and the aluminum substrate used in the production method of the present invention are applied. Each processing step is described in detail.

<First Aspect> As shown in FIGS. 1A to 1E , the metal-filled microstructure 10 can be produced by a production method including the following steps: an anodizing treatment step of performing anodization on one side of the aluminum substrate 1 An anodized film 4 having micropores 2 present in the thickness direction and a barrier layer 3 present at the bottom of the micropores 2 is formed on one surface of the aluminum substrate 1 (see FIGS. 1A and 1B). The barrier layer removing step, after the anodizing treatment step, removing the barrier layer 3 of the anodized film 4 (refer to FIG. 1B and FIG. 1C); the metal filling step, after the barrier layer removing step, in the micropore 2 The inner filler metal 5b (metal M2) (see FIGS. 1C and 1D); and the substrate removal step, after the metal filling step, the aluminum substrate 1 is removed (see FIGS. 1D and 1E). Here, the manufacturing method of the present invention is as described above, characterized in that in the barrier layer removing step, an aqueous alkali solution containing a metal M1 having a hydrogen overvoltage higher than aluminum is used, whereby the anodized film 4 is used. While the barrier layer 3 is removed, a metal layer containing the metal 5a (metal M1) is formed on the bottom of the micropores 2 (see FIGS. 1C, 2C, and 3C).

<Second Aspect> The production method of the present invention preferably includes at least one step of a surface metal protruding step and a back metal protruding step which will be described later. For example, as shown in FIGS. 2A to 2G (hereinafter, collectively referred to as "FIG. 2"), the metal-filled microstructure 10 can be produced by a manufacturing method including the following steps: an anodizing treatment step, Anodization treatment is performed on one surface of the aluminum substrate 1, and an anodized film 4 having micropores 2 present in the thickness direction and present at the bottom of the micropores 2 is formed on one surface of the aluminum substrate 1. a barrier layer 3 (refer to FIGS. 2A and 2B); a barrier layer removing step, after the anodizing treatment step, removing the barrier layer 3 of the anodized film 4 (refer to FIGS. 2B and 2C); a metal filling step, After the barrier layer removing step, the inside of the micropores 2 is filled with a metal 5b (metal M2) (refer to FIG. 2C and FIG. 2D); a surface metal protruding step, after the metal filling step, the anodized film 4 is not provided with aluminum. The surface on the side of the substrate 1 is partially removed in the thickness direction, so that the metal 5 filled in the metal filling step is more prominent than the surface of the anodized film 4 (refer to FIGS. 2D and 2E); the substrate removal step is performed on the surface metal After the step, will The substrate 1 is removed (refer to FIGS. 2E and 2F); and the back metal protruding step, after the substrate removing step, the surface of the anodized film 4 on the side where the aluminum substrate 1 is provided is partially removed in the thickness direction, so that the metal filling step The metal 5 filled in is more prominent than the surface of the anodized film 4 (see FIGS. 2F and 2G). Here, the manufacturing method of the present invention may include a surface metal protruding step and a back metal protruding step (hereinafter collectively referred to as "metal protruding step") as shown in the second aspect of FIG. It may also be an aspect including only one of the surface metal protruding step and the back metal protruding step.

<Third Aspect> The production method of the present invention preferably includes a resin layer forming step which will be described later. For example, as shown in FIGS. 3A to 3F (hereinafter, collectively referred to as "FIG. 3"), the metal-filled microstructures 10 and the metal-filled microstructures 10 can be manufactured by a manufacturing method including the following steps. Production: an anodizing treatment step of performing anodizing treatment on one side of the aluminum substrate 1 to form an anodized film 4 having a micropore 2 present in the thickness direction and present on one surface of the aluminum substrate 1 The barrier layer 3 at the bottom of the micropores 2 (refer to FIGS. 3A and 3B); the barrier layer removing step, after the anodizing treatment step, the barrier layer 3 of the anodized film 4 is removed (refer to FIG. 3B and FIG. 3C); metal filling step, after the barrier layer removing step, filling the inside of the micropores 2 with metal 5b (metal M2) (refer to FIGS. 3C and 3D); resin layer forming step, after the metal filling step, at the anode A resin layer is provided on the surface of the oxide film 4 on the side where the aluminum substrate 1 is not provided (see FIGS. 3D and 3E); and a substrate removal step is performed after the resin layer forming step (see FIGS. 3E and 3F). ). Here, the third aspect shown in FIG. 3 is an aspect in which the produced metal-filled microstructure 20 is wound up in a roll shape (see FIG. 4), and the resin layer 7 is used at the time of use. Peeling can be used, for example, as an anisotropic conductive member.

<Other Aspects> The manufacturing method of the present invention may be an aspect in which both the second aspect shown in FIG. 2 and the third aspect shown in FIG. 3 are satisfied, that is, the anodizing described above is sequentially included. The processing step, the barrier layer removing step, the metal filling step, the surface metal protruding step, the resin layer forming step, the substrate removing step, and the back metal protruding step are the same. In addition, the manufacturing method of the present invention may be an aspect shown in FIG. 2 of Patent Document 1 (International Publication No. 2015/029881), that is, an anode is applied to a part of the surface of the aluminum substrate using a mask layer of a desired shape. The state of oxidation treatment.

[Aluminum Substrate] The aluminum substrate used in the production method of the present invention is not particularly limited, and specific examples thereof include a pure aluminum plate; an alloy plate containing aluminum as a main component and containing a trace amount of an impurity element; and low-purity aluminum (for example) A substrate obtained by vapor-depositing high-purity aluminum on a recycled material, and coated with high-purity aluminum on the surface of a silicon wafer, quartz, glass, or the like by vapor deposition or sputtering. a substrate; a resin substrate having an aluminum laminated or the like.

In the present invention, in the aluminum substrate, the surface of the anodized film is preferably provided with an aluminum purity of 99.5% by mass or more, more preferably 99.9% by mass or more, and still more preferably 99.99% by mass or more. When the aluminum purity is in the above range, the regularity of the arrangement of the micropores becomes sufficient.

Further, in the present invention, it is preferred that the surface of the aluminum substrate to be subjected to the anodizing treatment step described later is subjected to heat treatment, degreasing treatment, and mirror finishing treatment in advance. Here, the heat treatment, the degreasing treatment, and the mirror finishing treatment can be carried out in the same manner as the respective treatments described in paragraphs [0044] to [0054] of JP-A-2008-270158.

[Anodic oxidation treatment step] The anodization step is a step of forming an anodized film on one surface of the aluminum substrate by performing anodization treatment on one side of the aluminum substrate, the anodized film having a presence a micropore in the thickness direction and a barrier layer present at the bottom of the micropore. The anodizing treatment in the production method of the present invention can be carried out by a conventionally known method, and from the viewpoint of improving the regularity of the arrangement of the micropores and ensuring the anisotropic conductivity of the metal-filled fine structure, it is preferred to use the self-regularization method. Or constant voltage processing. Here, the self-regularization method or the constant voltage treatment of the anodizing treatment can be carried out in the same manner as the respective processes described in the paragraphs [0056] to [0108] and [FIG. 3] of JP-A-2008-270158. deal with.

In the present invention, with respect to the anodizing treatment step, the metal-filled microstructures produced by the production method of the present invention (especially the third aspect described above) are rolled as shown in FIG. From the viewpoint of the shape supply on the winding core 21 having a predetermined diameter and a predetermined width, it is preferable that the anodized film formed by the anodizing treatment has an average thickness of 30 μm or less, more preferably 5 μm to 20 μm. . Among them, regarding the average thickness, the anodic oxide film is cut in the thickness direction using a Focused Ion Beam (FIB), and is subjected to Field Emission Scanning Electron Microscope (FE-SEM). The photograph of the surface of the cross-section was taken (magnification: 50,000 times), and the average thickness was calculated as the average value measured at 10 points.

[Block barrier removal step] The barrier layer removal step is to remove the barrier layer of the anodized film using an aqueous alkali solution containing a metal M1 having a hydrogen overvoltage higher than aluminum after the anodizing treatment step. step. In the manufacturing method of the present invention, the barrier layer is removed by the barrier layer removing step, and as shown in FIG. 1C, a metal layer 5a containing the metal M1 is formed at the bottom of the micropores 2. Here, the hydrogen overvoltage refers to a voltage necessary for generating hydrogen, for example, the hydrogen overvoltage of aluminum (Al) is -1.66 V (J. J. Chem., 1982, (8), p1305-1313). Further, an example of the metal M1 higher than the hydrogen overvoltage of aluminum and the value of the hydrogen overvoltage thereof are shown below. <Metal M1 and hydrogen (1N H ₂ SO ₄ ) overvoltage> · Platinum (Pt): 0.00 V · Gold (Au): 0.02 V · Silver (Ag): 0.08 V · Nickel (Ni): 0.21 V · Copper ( Cu): 0.23 V · tin (Sn): 0.53 V · zinc (Zn): 0.70 V

In the present invention, in the barrier layer removal step, the substitution reaction with the metal M2 filled in the anodizing treatment step described later is less affected by the electrical characteristics of the metal filled in the inside of the micropores. The metal M1 to be used is preferably a metal having a higher ionization tendency than the metal M2 used in the metal filling step described later. Specifically, when copper (Cu) is used as the metal M2 in the metal filling step described later, the metal M1 used in the barrier layer removing step may, for example, be Zn, Fe, Ni, Sn, or the like. In order to use Zn or Ni, it is more preferable to use Zn. In the case where Ni is used as the metal M2 in the metal filling step to be described later, examples of the metal M1 used in the barrier layer removing step include Zn, Fe, and the like. Among them, Zn is preferably used.

The method of removing the barrier layer by using an aqueous alkali solution containing such a metal M1 is not particularly limited, and examples thereof include the same methods as the conventionally known chemical etching treatment.

<Chemical etching treatment> Regarding the removal of the barrier layer by the chemical etching treatment, for example, only the barrier layer can be selectively dissolved by immersing the structure after the anodizing treatment step in an aqueous alkali solution After the aqueous alkali solution is filled into the inside of the micropores, the pH buffer is brought into contact with the surface on the opening side of the micropores of the anodized film.

Here, the aqueous alkali solution containing the metal M1 is preferably an aqueous solution using at least one base selected from the group consisting of sodium hydroxide, potassium hydroxide and lithium hydroxide. Further, the concentration of the aqueous alkali solution is preferably from 0.1% by mass to 5% by mass. The temperature of the aqueous alkali solution is preferably from 10 ° C to 60 ° C, more preferably from 15 ° C to 45 ° C, still more preferably from 20 ° C to 35 ° C. Specifically, for example, a 50 g/L aqueous solution of phosphoric acid at 40° C., a sodium hydroxide aqueous solution of 0.5 g/L and 30° C., an aqueous potassium hydroxide solution of 0.5 g/L and 30° C., or the like can be preferably used. Further, as the pH buffer, a buffer corresponding to the aqueous alkali solution described above can be suitably used.

Further, the immersion time in the aqueous alkali solution is preferably from 5 minutes to 120 minutes, more preferably from 8 minutes to 120 minutes, further preferably from 8 minutes to 90 minutes, and particularly preferably from 10 minutes to 90 minutes. Among them, it is preferably from 10 minutes to 60 minutes, more preferably from 15 minutes to 60 minutes.

[Metal Filling Step] The metal filling step is a step of performing electrolytic plating treatment to fill the inside of the micropores in the anodized film with the metal M2 after the barrier layer removing step.

<Metal M2> The metal M2 is preferably a material having a specific resistance of 10 ³ Ω·cm or less, and specific examples thereof are preferably exemplified by gold (Au), silver (Ag), copper (Cu), and aluminum (Al). ), magnesium (Mg), nickel (Ni), zinc (Zn), indium-doped tin oxide (Indium Tin Oxide (ITO)), and the like. Among them, from the viewpoint of conductivity, Cu, Au, Al, and Ni are preferable, Cu or Au is more preferable, and Cu is further preferable.

<Filling Method> The electrolytic plating treatment method in which the metal M2 is filled in the inside of the micropores can be, for example, an electrolytic plating method or an electroless plating method. Here, in the conventionally known electrolytic plating method for coloring or the like, it is difficult to selectively precipitate (grow) metal in a high aspect ratio in a hole. The reason for this is considered to be that the precipitated metal is consumed in the pores, and the plating does not grow even if electrolysis is performed for a certain period of time or longer.

Therefore, in the production method of the present invention, when the metal is filled by the electrolytic plating method, it is necessary to set the rest time at the time of pulse wave electrolysis or constant potential electrolysis. The rest time must be 10 seconds or longer, preferably 30 seconds to 60 seconds. Further, in order to promote the stirring of the electrolytic solution, it is desirable to apply ultrasonic waves. Further, the electrolysis voltage is usually 20 V or less, preferably 10 V or less, and it is preferable to measure the deposition potential of the target metal in the electrolytic solution to be used in advance, and carry out constant potential electrolysis at a potential of +1 V or less. Furthermore, in the case of constant potential electrolysis, it is desirable to use cyclic voltammetry in combination with Solartron, BAS, Hokuto Denko, and IVIUM. A potentiostat device such as a company.

As the plating solution, a previously known plating solution can be used. Specifically, in the case of depositing copper, an aqueous copper sulfate solution is usually used, and the concentration of copper sulfate is preferably from 1 g/L to 300 g/L, more preferably from 100 g/L to 200 g/L. Further, when hydrochloric acid is added to the electrolytic solution, precipitation can be promoted. In this case, the hydrochloric acid concentration is preferably from 10 g/L to 20 g/L. Further, in the case of depositing gold, it is preferred to perform plating by alternating current electrolysis using a sulfuric acid solution of tetrachlorogold.

Further, in the electroless plating method, it takes a long time to completely fill the metal in the pores including the micropores having a high aspect ratio, and therefore, in the production method of the present invention, it is desirable to fill by the electrolytic plating method. metal.

In the present invention, it is considered that the barrier layer is removed by the barrier layer removing step, and a metal layer including the metal M1 described above is formed at the bottom of the micropore, so as described above, by plating The generation of hydrogen by the liquid is suppressed, and metal filling by electrolytic plating is easily performed.

[Substrate Removal Step] The substrate removal step is a step of removing the aluminum substrate after the metal filling step to obtain a metal-filled microstructure. The method for removing the aluminum substrate is not particularly limited, and for example, a method of removing by dissolution or the like is preferably exemplified.

<Dissolution of Aluminum Substrate> The dissolution of the aluminum substrate is preferably a treatment liquid in which it is difficult to dissolve the anodized film and dissolve aluminum easily. The treatment liquid preferably has a dissolution rate of aluminum of 1 μm/min or more, more preferably 3 μm/min or more, and still more preferably 5 μm/min or more. Similarly, the dissolution rate of the anodized film is preferably 0.1 nm/min or less, more preferably 0.05 nm/min or less, and further preferably 0.01 nm/min or less. Specifically, it is preferably a treatment liquid containing at least one metal compound having a lower ionization tendency than aluminum and having a pH of 4 or less or 8 or more, more preferably a pH of 3 or less or 9 or more, and still more preferably 2 The following or 10 or more.

The treatment liquid is preferably an acid or alkali aqueous solution as a matrix, and is formulated with, for example, manganese, zinc, chromium, iron, cadmium, cobalt, nickel, tin, lead, antimony, bismuth, copper, mercury, silver, palladium, platinum. A treatment solution of a gold compound (for example, chloroplatinic acid), a fluoride of the metal, or a chloride of the metal. Among them, a substrate of an aqueous acid solution is preferred, and a chloride is preferably doped. Particularly, from the viewpoint of handling latitude, a treatment liquid (hydrochloric acid/mercuric chloride) in which an aqueous solution of hydrochloric acid is doped with mercuric chloride, and a treatment liquid in which copper chloride is doped in an aqueous hydrochloric acid solution are preferred ( Hydrochloric acid / copper chloride). In addition, the composition of such a treatment liquid is not particularly limited, and for example, a bromine/methanol mixture, a bromine/ethanol mixture, aqua regia, or the like can be used.

Further, the acid or alkali concentration of the treatment liquid is preferably from 0.01 mol/L to 10 mol/L, more preferably from 0.05 mol/L to 5 mol/L. Further, the treatment temperature for using such a treatment liquid is preferably from -10 °C to 80 °C, preferably from 0 °C to 60 °C.

Further, the dissolution of the aluminum substrate is performed by bringing the aluminum substrate after the metal filling step into contact with the treatment liquid described above. The method of contact is not particularly limited, and examples thereof include a dipping method and a spraying method. Among them, a dipping method is preferred. The contact time at this time is preferably from 10 seconds to 5 hours, more preferably from 1 minute to 3 hours.

[Metal protrusion step] In the production method of the present invention, the reason why the metal bondability of the produced metal-filled microstructure is improved is preferably as shown in the second aspect and FIG. 2 described above. The surface metal protruding step and/or the back metal protruding step are included. Here, the surface metal protruding step is to partially remove the surface of the anodized film on the side where the aluminum substrate is not disposed in the thickness direction after the metal filling step and before the substrate removing step. The step of making the metal M2 filled in the metal filling step more prominent than the surface of the anodized film. In addition, the back metal protruding step is to partially remove the surface of the anodized film on the side where the aluminum substrate is provided in the thickness direction after the substrate removing step, so that the metal filling step is filled. The step of the metal M2 being more prominent than the surface of the anodized film.

The partial removal of the anodized film in such a metal protrusion step can be performed, for example, by anodizing a film having micropores filled with metal, and not dissolving the metal M1 and the metal M2 described above (special It is a metal M2) and is in contact with an anodic oxide film, that is, an aqueous acid solution or an aqueous alkali solution of alumina. The method of contact is not particularly limited, and examples thereof include a dipping method and a spraying method. Among them, a dipping method is preferred.

In the case of using an aqueous acid solution, it is preferred to use an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid or hydrochloric acid or an aqueous solution of a mixture of these acids. Among them, in terms of excellent safety, an aqueous solution containing no chromic acid is preferred. The concentration of the aqueous acid solution is preferably from 1% by mass to 10% by mass. The temperature of the aqueous acid solution is preferably from 25 ° C to 60 ° C. Further, in the case of using an aqueous alkali solution, it is preferred to use an aqueous solution selected from at least one of a group consisting of sodium hydroxide, potassium hydroxide and lithium hydroxide. The concentration of the aqueous alkali solution is preferably from 0.1% by mass to 5% by mass. The temperature of the aqueous alkali solution is preferably from 20 ° C to 35 ° C. Specifically, for example, a 50 g/L aqueous solution of phosphoric acid at 40 ° C, an aqueous solution of sodium hydroxide at 0.5 g/L and 30 ° C, or an aqueous potassium hydroxide solution at 0.5 g/L and 30 ° C can be preferably used. The immersion time in the aqueous acid solution or the aqueous alkali solution is preferably from 8 minutes to 120 minutes, more preferably from 10 minutes to 90 minutes, and still more preferably from 15 minutes to 60 minutes. Here, in the case where the immersion treatment for a short period of time is repeated, the immersion time means the total of the immersion times. Further, a cleaning treatment may be performed between the respective immersion treatments.

Further, in the production method of the present invention, when the produced metal-filled microstructure is used as an anisotropic conductive member, the pressure-bonding property of the substrate to be bonded, such as a wiring board, is improved. The step of protruding the surface metal and/or the step of protruding the back metal is preferably a step of projecting the metal M2 from 10 nm to 1000 nm from the surface of the anodized film, more preferably from 50 nm to 500 nm.

Further, in the production method of the present invention, when the produced metal-filled microstructure is connected (joined) to the electrode by a method such as pressure bonding, the surface-direction insulation in the case where the protruding portion is crushed can be sufficiently ensured. For the reason of the nature, it is preferable that the aspect ratio (the height of the protruding portion / the diameter of the protruding portion) of the protruding portion formed by the surface metal protruding step and/or the back metal protruding step is 0.01 or more and less than 20, more preferably 6 to 20.

In the manufacturing method of the present invention, the metal-containing via path formed by the metal filling step and the substrate removing step and any metal protrusion step described above is preferably columnar, and the diameter thereof is preferably more than 5 nm. It is 10 μm or less, more preferably 40 nm to 1000 nm.

Further, the conductive paths are present in a state of being insulated from each other by an anodic oxide film of an aluminum substrate, and the density thereof is preferably 20,000/mm ² or more, more preferably 2,000,000/mm ² or more, and still more preferably 1000. More than 10,000/mm ² or more, particularly preferably 50 million/mm ² or more, and most preferably 100 million/mm ² or more.

Further, the distance between the centers of the adjacent conduction paths is preferably from 20 nm to 500 nm, more preferably from 40 nm to 200 nm, and even more preferably from 50 nm to 140 nm.

[Resin layer forming step] In the production method of the present invention, the reason why the transportability of the produced metal-filled fine structure is improved is preferably as described in the third aspect and FIG. Including a resin layer forming step. Here, the resin layer forming step is after the metal filling step (after the surface metal protruding step in the case of the surface metal protruding step) and before the substrate removing step, the anodizing A step of providing a resin layer on the surface of the film on the side where the aluminum substrate is not provided.

Specific examples of the resin material constituting the resin layer include an ethylene copolymer, a polyamide resin, a polyester resin, a polyurethane resin, a polyolefin resin, an acrylic resin, and a cellulose system. The resin layer or the like is preferably a peelable adhesive layer-attached film from the viewpoint of transportability and easy to use as an anisotropic conductive member, and more preferably by heat treatment or ultraviolet exposure treatment. A film with an adhesive layer that is weakened and becomes peelable.

The film to which the adhesive layer is attached is not particularly limited, and examples thereof include a heat-peelable resin layer or an ultraviolet (UV) peel-off resin layer. Here, the heat-peelable resin layer has an adhesive force at normal temperature and can be easily peeled off only by heating, and a resin layer such as a microcapsule which is mainly foamed is mainly used. Further, specific examples of the adhesive constituting the adhesive layer include a rubber-based adhesive, an acrylic adhesive, a vinyl alkyl ether adhesive, an anthrone-based adhesive, a polyester adhesive, and a polyamide. An adhesive, a urethane-based adhesive, a styrene-diene block copolymer-based adhesive, or the like. Further, the UV-peelable resin layer has a UV-curable adhesive layer, which loses adhesion by curing and becomes peelable. The UV-curable adhesive layer may, for example, be a polymer in which a carbon-carbon double bond is introduced into a polymer side chain or a main chain or a main chain terminal in a matrix polymer. The matrix polymer having a carbon-carbon double bond is preferably a polymer having an acrylic polymer as a basic skeleton. Further, the acrylic polymer is crosslinked, and a polyfunctional monomer or the like may be contained as a monomer component for copolymerization as necessary. The matrix polymer having a carbon-carbon double bond may be used singly or as a UV curable monomer or oligomer. The UV-curable adhesive layer is cured by UV irradiation, and a photopolymerization initiator is preferably used in combination. Examples of the photopolymerization initiator include a benzoin ether compound; a ketal compound; an aromatic sulfonium chloride compound; a photoactive oxime compound; a benzophenone compound; a thioxanthone compound; Halogenated ketone; mercaptophosphine oxide; acylphosphonate and the like.

Commercial products of the heat-peelable resin layer include, for example, WS5130C02, WS5130C10, etc. [Intelimer] [registered trademark] tape (manufactured by Nitta Co., Ltd.); Somatac [registered] Trademark] TE series (made by Somar); No. 3198, No. 3198LS, No. 3198M, No. 3198MS, No. 3198H, No. 3195, No. 3196, No. 3195M, No. 3195MS No. 3195H, No. 3195HS, No. 3195V, No. 3195VS, No. 319Y-4L, No. 319Y-4LS, No. 319Y-4M, No. 319Y-4MS, No. 319Y-4H, No. 319Y - 4HS, No. 319Y-4LSC, No. 31935MS, No. 31935HS, No. 3193M, No. 3193MS, etc., etc. (Revalpha) [registered trademark] series (manufactured by Nitto Denko Corporation).

Commercial products of the UV-peelable resin layer include, for example, ELP DU-300, ELP DU-2385KS, ELP DU-2187G, ELP NBD-3190K, ELP UE-2091J, and the like, Elepholder [registered trademark] ( Nitto Denko Co., Ltd.); Adwill D-210, Adwill D-203, Adwill D-202, Adwill D-175, Ade Adwill D-675 (both manufactured by Lintec Co., Ltd.); Sumilite [registered trademark] FLS N8000 series (manufactured by Sumitomo Bakelite Co., Ltd.); Dicing tape such as UC353EP-110 (manufactured by Furukawa Electric Co., Ltd.); or ELP RF-7232DB, ELP UB-5133D (all manufactured by Nitto Denko Corporation); SP-575B-150, SP-541B -205, SP-537T-160, SP-537T-230 (both manufactured by Furukawa Electric Co., Ltd.) and other back grind tapes.

Further, the method of attaching the film with the adhesive layer is not particularly limited, and it can be attached by using a conventionally known surface protective tape attaching device or a laminating machine.

[Winding step] In the production method of the present invention, it is preferable to include a roll after the resin layer forming step described above, for the reason that the transportability of the produced metal-filled fine structure is further improved. In the step, the metal-filled microstructure is wound into a roll shape in a state of having the resin layer. Here, the winding method in the winding step is not particularly limited, and for example, a method of winding up to a winding core 21 having a predetermined diameter and a predetermined width as shown in FIG. 4 can be cited.

Further, in the production method of the present invention, from the viewpoint of facilitating the winding in the winding step, it is preferable that the metal-filled microstructure having the resin layer has an average thickness of 30 μm or less, more preferably It is 5 μm to 20 μm. In addition, regarding the average thickness, the metal-filled fine structure excluding the resin layer was subjected to a cutting process in the thickness direction by FIB, and a surface photograph (magnification: 50,000 times) of the cross-section was taken by FE-SEM, and measured at 10 points. The average thickness is calculated as the average value.

[Other Processing Procedures] The manufacturing method of the present invention may include the polishing steps described in paragraphs [0049] to [0057] of Patent Document 1 (International Publication No. 2015/029881), in addition to the above-described respective steps. Surface smoothing step, protective film forming treatment, and water washing treatment. Further, from the viewpoint of operability in production or use of a metal-filled fine structure as an anisotropic conductive member, various processes or forms as described below are applied.

<Processing Example of Using Temporary Adhesive Agent> In the present invention, after the metal-filled fine structure is obtained by the substrate removing step, the following steps are included: the metal is filled with a temporary adhesive (Temporary Bonding Materials) The structure is fixed on the germanium wafer and thinned by grinding. Then, after the step of thinning, after the surface is sufficiently cleaned, the surface metal protruding step is performed. Then, after the temporary adhesive which is stronger than the previous temporary adhesive is applied to the surface on which the metal protrudes and is fixed on the germanium wafer, the germanium wafer which is followed by the previous temporary adhesive is peeled off. The back metal protruding step is performed on the surface of the peeled metal-filled fine structure side.

<Processing Example of Using Wax (WAX)> In the present invention, after the metal-filled microstructure is obtained by the substrate removing step, the method includes the steps of: fixing the metal-filled microstructure to the twin by using wax. On the circle, thinning is performed by grinding. Then, after the step of thinning, after the surface is sufficiently cleaned, the surface metal protruding step is performed. Then, after applying a temporary adhesive to the surface on which the metal protrudes and fixing it on the ruthenium wafer, the ruthenium wafer is peeled off by melting the previous wax by heating, and the fine structure side is filled with the peeled metal. The surface performs the back metal protrusion step. Further, a solid wax can also be used, and the uniformity of coating thickness can be improved by using Skycoat (manufactured by Nissin Seiko Co., Ltd.).

<Processing Example of Subsequent Substrate Removal Process> In the present invention, after the metal filling step and before the substrate removing step, the following steps may be included: using a temporary adhesive, wax or a functional adsorption film to aluminum After the substrate is fixed on a rigid substrate (for example, a germanium wafer, a glass substrate, or the like), the surface of the anodized film on the side where the aluminum substrate is not provided is thinned by polishing. Then, after the step of thinning, after the surface is sufficiently cleaned, the surface metal protruding step is performed. Then, after coating a resin material (for example, an epoxy resin, a polyimide resin, or the like) as an insulating material on the surface on which the metal protrudes, the rigidity is attached to the surface thereof by the same method as described above. Substrate. In the attachment by the resin material, a material having a bonding force greater than that of a temporary adhesive or the like can be selected, and after the bonding with the resin material, the rigid substrate to be attached first is peeled off, and the above-described method is sequentially performed. A substrate removal step, a polishing step, and a back metal protrusion processing step. Further, as the functional adsorption film, Q-chuck (registered trademark) (manufactured by Maruishi Co., Ltd.) or the like can be used.

In the present invention, it is preferable that the metal-filled microstructure is provided in the form of a product in a state of being attached to a rigid substrate (for example, a germanium wafer, a glass substrate, or the like) by a peelable layer. In such a supply mode, when a metal-filled fine structure is used as the bonding member, the surface of the metal-filled microstructure can be temporarily attached to the surface of the device, and the rigid substrate can be peeled off to become a device to be connected. The upper and lower devices are joined by a metal-filled fine structure by heat-compression bonding at an appropriate portion. Further, as the peelable layer, a heat peeling layer can be used, and a light peeling layer can also be used in combination with a glass substrate.

Further, in the production method of the present invention, each step described above can be carried out in a single sheet, and the coil of aluminum can be continuously processed in a web. Further, in the case of continuous treatment, it is preferred to provide an appropriate washing step and drying step between the respective steps.

A metal-filled microstructure having a microporous layer provided in an insulating substrate derived from an anodized film containing an aluminum substrate can be obtained by the production method of the present invention including such processing steps. The inside of the through hole is made of metal. Specifically, by the production method of the present invention, for example, an anisotropic conductive member described in JP-A-2008-270158, that is, an insulating substrate (anodized film of an aluminum substrate having micropores) can be obtained. In the insulating substrate, the plurality of conductive paths including the conductive member (metal) are insulated from each other in the thickness direction, and one end of each of the conductive paths is on the insulating base One surface of the material is exposed, and the other end of each of the conduction paths is exposed on the other surface of the insulating base material, and an anisotropic conductive member is provided in such a state. [Examples]

Hereinafter, the invention will be specifically described by way of examples. However, the invention is not limited to the embodiments.

[Example 1] <Preparation of aluminum substrate> 0.06 mass% of Si, 0.30 mass% of Fe, 0.005 mass% of Cu, 0.001 mass% of Mn, 0.001 mass% of Mg, 0.001 mass% of Zn, and 0.03 were used. Aluminium alloy with a mass % of Ti and a balance of Al and unavoidable impurities to prepare a molten metal, which is subjected to molten metal treatment and filtration, and is formed by direct chilling (Direct Chill, DC) casting method to a thickness of 500 mm. Ingots with a width of 1200 mm. Then, after the surface was cut by an average cutting thickness of 10 mm by a plane cutting machine, the soaking was maintained at 550 ° C for about 5 hours, and when the temperature was lowered to 400 ° C, a hot rolling mill was used to make a rolled sheet having a thickness of 2.7 mm. . Then, after heat treatment at 500 ° C using a continuous annealing machine, it was finished by cold rolling to a thickness of 1.0 mm to obtain an aluminum substrate of Japanese Industrial Standards (JIS) 1050 material. After the aluminum substrate was set to have a width of 1030 mm, each treatment described below was carried out.

<Electrochemical Polishing Treatment> An electrolytic polishing treatment was carried out on the aluminum substrate using an electrolytic polishing liquid having the following composition under the conditions of a voltage of 25 V, a liquid temperature of 65 ° C, and a liquid flow rate of 3.0 m/min. The cathode was set to a carbon electrode, and the power source was GP0110-30R (manufactured by Takasago Manufacturing Co., Ltd.). Further, the flow rate of the electrolytic solution was measured using a vortex flow monitor FLM22-10PCW (manufactured by As-One Co., Ltd.). (Electrochemical polishing composition) ·85 mass% phosphoric acid (reagent manufactured by Wako Pure Chemical Industries, Ltd.) 660 mL ·Pure water 160 mL ·Sulfuric acid 150 mL ·Glycol 30 mL

<Anodic Oxidation Treatment Step> Next, the aluminum substrate after the electrolytic polishing treatment is subjected to anodization treatment by a self-regularization method in the order described in Japanese Laid-Open Patent Publication No. 2007-204802. The aluminum substrate after electrolytic polishing was subjected to pre-anodizing treatment for 5 hours under the conditions of a voltage of 40 V, a liquid temperature of 16 ° C, and a liquid flow rate of 3.0 m/min using an electrolyte of 0.50 mol/L oxalic acid. Thereafter, a release treatment of immersing the pre-anodized aluminum substrate in a mixed aqueous solution of 0.2 mol/L of anhydrous chromic acid and 0.6 mol/L of phosphoric acid (liquid temperature: 50 ° C) for 12 hours was carried out. Then, using an electrolyte of 0.50 mol/L oxalic acid, a re-anodizing treatment was carried out for 3 hours and 45 minutes under the conditions of a voltage of 40 V, a liquid temperature of 16 ° C, and a liquid flow rate of 3.0 m/min to obtain a film thickness of 30 μm. Anodized film. Further, both the pre-anodizing treatment and the re-anodizing treatment were performed such that the cathode was set to a stainless steel electrode, and the power source was GP0110-30R (manufactured by Takasago Manufacturing Co., Ltd.). In addition, the cooling device is a NeoCool BD36 (manufactured by Yamato Scientific Co., Ltd.), and the stirring and warming device is a Piperrrer PS-100 (EYELA Tokyo Physical and Chemical Equipment Co., Ltd.). Manufacturing). Further, the flow rate of the electrolytic solution was measured using a vortex flow monitor FLM22-10PCW (manufactured by As-One Co., Ltd.).

<Blocking Layer Removal Step> Then, after the anodizing treatment step, an aqueous alkali solution obtained by dissolving copper (II) hydroxide in NaOH (48%) and diluting with water to 50 g/L using NaOH was used. The etching treatment was performed by immersing at 30 ° C for 150 seconds, and the barrier layer located at the bottom of the micropores of the anodized film was removed, and copper (metal M1) was simultaneously deposited on the surface of the exposed aluminum substrate. Further, the average thickness of the anodized film after the barrier layer removing step was 30 μm.

<Metal Filling Step> Next, an electrolytic plating treatment is performed using an aluminum substrate as a cathode and platinum as a positive electrode. Specifically, constant current electrolysis was carried out using a nickel plating solution having the composition shown below, and a metal-filled fine structure in which nickel was filled in the inside of the micropores was produced. Here, the constant current electrolysis is performed by using a plating apparatus manufactured by Yamamoto Gold Plating Co., Ltd., using a power source (HZ-3000) manufactured by Hokuto Electric Co., Ltd., and performing a cyclic voltammetry to confirm the precipitation potential in the plating solution. Thereafter, the treatment was carried out under the conditions shown below. (Nickel plating composition and conditions) ·Ni(NH ₂ SO ₃ ) ₂ ·4H ₂ O 1.24 mol/L ·NiCl ₂ ·6H ₂ O 0.04 mol/L ·H ₃ BO ₃ 0.49 mol/L ·Current density 1 A/dm ² · Electrolyte temperature 40 ° C · Electrolysis time Adjust to 30 μm (test on Cu plate)

The surface of the anodized film in which the metal was filled in the micropores was observed by FE-SEM, and the presence or absence of the sealing of the metal in the 1000 micropores was observed, and the sealing ratio (the number of the closed micropores / 1000), the result is 98%. In addition, the anodized film in which the metal was filled in the micropores was subjected to cutting in the thickness direction by FIB, and a photograph of the surface of the cross section was taken by FE-SEM (magnification: 50,000 times), and the inside of the micropores was confirmed. In the sealed micropores, the inside is completely filled with metal.

<Substrate Removal Step> Then, the aluminum substrate was dissolved and removed by immersing in a mixed solution of copper chloride/hydrochloric acid to prepare a metal-filled microstructure having an average thickness of 30 μm. The diameter of the via in the fabricated metal-filled microstructure was 60 nm, the pitch between the vias was 100 nm, and the density of the vias was 57.7 million/mm ² .

[Example 2] The aqueous alkali solution used in the barrier layer removal step was changed to "an aqueous alkali solution in which nickel chloride was dissolved in NaOH (48%) and water was diluted with NaOH to 50 g/L" In addition, the plating solution used in the metal filling step was changed to the zinc plating solution having the composition shown below, and the plating treatment was performed under the conditions shown below, except for the same conditions as in Example 1. A metal-filled microstructure having an average thickness of 30 μm was produced. (Zinc plating solution composition and conditions) · Sodium hydroxide 100 g / L · Zn 10 g / L · Current density 1 A / dm ² · Electrolyte temperature 50 ° C · Electrolysis time is adjusted to 50 μm (in Cu Board test)

[Example 3] The plating solution used in the metal filling step was changed to the copper plating solution having the composition shown below, and the plating treatment was performed under the conditions shown below. A metal-filled microstructure having an average thickness of 30 μm was produced under the same conditions. (Composition and conditions of copper plating solution) · Copper sulfate 100 g / L · Sulfuric acid 50 g / L · Hydrochloric acid 15 g / L · Temperature 25 ° C · Current density 10 A / dm ²

[Example 4] The alkali aqueous solution used in the barrier layer removal step was changed to "an aqueous alkali solution obtained by dissolving zinc oxide in an aqueous sodium hydroxide solution (50 g/l) at 2000 ppm). A metal-filled microstructure having an average thickness of 30 μm was produced under the same conditions as in Example 3.

[Example 5] Between the metal filling step and the substrate removing step, an epoxy resin [EPICON (registered trademark) D-591 was coated on the surface of the anodized film on the side where the aluminum substrate was not provided, A metal-filled microstructure was produced under the same conditions as in Example 4 except that an epoxy resin layer having a film thickness of 2 μm was formed. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 6] Between the metal filling step and the substrate removing step, a soluble polyimine (Solpit-6,6-PI) was coated on the surface of the anodized film on the side where the aluminum substrate was not provided. A metal-filled microstructure was produced under the same conditions as in Example 4 except that a polyimine resin layer having a film thickness of 2 μm was formed by Solphi Industries Co., Ltd. (manufactured by Solpit Industries Co., Ltd.). Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 7] Between the metal filling step and the substrate removing step, an epoxy resin [EPICON (registered trademark) D-591 was coated on the surface of the anodized film on the side where the aluminum substrate was not provided, A metal-filled microstructure was produced under the same conditions as in Example 4 except that an epoxy resin layer having a film thickness of 20 μm was formed. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 8] Between the metal filling step and the substrate removing step, a soluble polyimine (Solpit-6,6-PI) was coated on the surface of the anodized film on the side where the aluminum substrate was not provided. A metal-filled microstructure was produced under the same conditions as in Example 4 except that a polyimine resin layer having a film thickness of 20 μm was formed by Solphi Industries Co., Ltd. (manufactured by Solpit Industries Co., Ltd.). Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 9] A resin substrate [Q-Chuck single-sided product was pressed between the metal filling step and the substrate removing step on the surface of the anodized film on the side where the aluminum substrate was not provided. A metal-filled microstructure was produced under the same conditions as in Example 4 except that H-type (Type-H) (78 μm thick) was produced by Maruza Co., Ltd. Further, the average thickness of the metal-filled fine structure excluding the resin substrate is as shown in Table 1 below.

[Example 10] A metal-filled microstructure was produced under the same conditions as in Example 9 except that the following surface metal protrusion step was carried out between the metal filling step and the resin layer forming step. Further, the average thickness of the metal-filled fine structure excluding the resin substrate is as shown in Table 1 below. <Surface metal protrusion step> The structure after the metal filling step is immersed in an aqueous sodium hydroxide solution (concentration: 5% by mass, liquid temperature: 20° C.), and the immersion time is adjusted so that the height of the protruding portion becomes 5 nm. The surface of the anodized film of aluminum is selectively dissolved, and a structure in which copper as a filler metal protrudes is produced.

[Example 11] A metal-filled microstructure was produced in the same manner as in Example 10 except that the following back metal protrusion step was carried out after the substrate removal step. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below. <Back metal protruding step> The structure after the substrate removal step is immersed in an aqueous sodium hydroxide solution (concentration: 5% by mass, liquid temperature: 20° C.), and the immersion time is adjusted so that the height of the protruding portion becomes 5 nm. The surface of the anodized film of aluminum is selectively dissolved, and a structure in which copper as a filler metal protrudes is produced.

[Example 12] A metal-filled microstructure was produced in the same manner as in Example 11 except that the immersion time was adjusted so that the height of the protruding portion in each of the surface metal protruding step and the back metal protruding step was 50 nm. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 13] A metal-filled microstructure was produced in the same manner as in Example 12 except that the resin layer formation step was not carried out. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 14] A metal-filled microstructure was produced in the same manner as in Example 11 except that the immersion time was adjusted so that the height of the protruding portion in each of the surface metal protruding step and the back metal protruding step was 200 nm. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 15] A resin substrate with a heat-peelable adhesive layer (Revalpha 3195HS, manufactured by Nitto Denko Corporation) was attached instead of a resin substrate [Q-Chuck single-sided product] A metal-filled microstructure was produced in the same manner as in Example 12 except that H-type (Type-H) (78 μm thick) was produced by Maruza Co., Ltd. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 16] The immersion time was adjusted so that the height of the protruding portion in each of the surface metal protruding step and the back metal protruding step became 500 nm, and the UV-peelable adhesive layer-attached resin substrate (ELP DU-300) was attached. , manufactured by Nitto Denko Co., Ltd.), in addition to the resin substrate [Q-Chuck, single-sided product type H (Type-H) (78 μm thick), manufactured by Maruishi Co., Ltd.], A metal-filled microstructure was produced in the same manner as in Example 11. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 17] A metal-filled microstructure was produced in the same manner as in Example 15 except that the immersion time was adjusted so that the height of the protruding portion in each of the surface metal protruding step and the back metal protruding step was 500 nm. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 18] A metal-filled microstructure was produced in the same manner as in Example 15 except that the immersion time was adjusted so that the height of the protruding portion in each of the surface metal protruding step and the back metal protruding step was 5000 nm. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 19] A metal-filled microstructure was produced in the same manner as in Example 17 except that the treatment time of the re-anodizing treatment in the anodizing treatment step was changed to 10 hours. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 20] The immersion time was adjusted so that the height of the protruding portion in each of the surface metal protruding step and the back metal protruding step was 200 nm, and each processing step was carried out by mesh transportation, and other examples were used. The same method was used to produce a metal-filled microstructure. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 21] A metal-filled microstructure was produced in the same manner as in Example 20 except that the treatment time of the re-anodizing treatment in the anodizing treatment step was changed to 1 hour and 15 minutes. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Example 22] The immersion time was adjusted so that the height of the protruding portion in each of the surface metal protruding step and the back metal protruding step was 500 nm, and the treatment time of the re-anodizing treatment in the anodizing treatment step was changed to 7 hours. A metal-filled microstructure was produced in the same manner as in Example 20 except for the above. Further, the average thickness of the metal-filled fine structure excluding the resin layer is as shown in Table 1 below.

[Comparative Example 1] The same conditions as in Example 4 were carried out except that the aqueous alkali solution used in the barrier layer removal step was changed to "aqueous sodium hydroxide solution (50 g/l)" without performing the substrate removal step. A metal-filled microstructure is fabricated underneath. Further, the average thickness of the metal-filled fine structure excluding the aluminum substrate is as shown in Table 1 below.

[Comparative Example 2] A metal-filled microstructure was produced under the same conditions as in Example 4 except that the aqueous alkali solution used in the barrier layer removal step was changed to "aqueous sodium hydroxide (50 g/l)". Further, the average thickness of the metal-filled microstructure was as shown in Table 1 below.

[Evaluation] For each of the metal-filled fine structures produced in Examples 1 to 22 and Comparative Examples 1 to 2, the transportability, in-plane uniformity, separation property, and two-sided pressure were evaluated by the following methods. Connectivity. The results of these evaluations are shown in Table 1 below.

<Transportability> The metal-filled fine structure in which the resin layer is not provided in each of the produced metal-filled fine structures is wound around a rubber-made roller 30 having a diameter of 100 mmf as shown in FIG. 5A. Go up and observe the surface state. On the other hand, as shown in FIG. 5B, the metal-filled fine structure 20 is placed between the two rubber rolls 30 having a diameter of 100 mmf and rotated, as shown in FIG. 5B. Observe the surface state. Furthermore, the width of the metal-filled microstructure was set to 310 mm. By setting it to 310 mm, it can be applied to sizes below 12” wafers. As a result of the observation, the state in which the surface was not cracked was evaluated as "A", and the state in which the crack was observed on the surface but not peeled off during the rotation was evaluated as "B", and cracks were observed on the surface, and local peeling was observed at the time of rotation. The state was evaluated as "C", and a state in which cracks were observed on the surface and was observed to fall off in the half portion at the time of rotation was evaluated as "D", and cracks were observed in the half of the set stage, and peeling occurred. The status is evaluated as "E".

<In-Plane Uniformity> In the production of each metal-filled microstructure, an image of an adjacent 10 field of view was taken in the lateral direction at a magnification of 50,000 times using FE-SEM immediately after the metal filling step, according to the non-metal The ratio of the number of filled micropores divided by the number of the total micropores was used to calculate the ratio of the number of micropores not filled with metal. When the ratio of the micropores not filled with metal was 1% or less, it was evaluated as "A", and when it was more than 1% and 2% or less, it was evaluated as "B", and when it was more than 2% and was 3% or less, it was evaluated as "C" is evaluated as "D" when it exceeds 3% and is 10% or less.

<Separation property> The resin-filled fine structure was prepared, and when the resin layer was not formed, when the resin layer was peeled off by hand, the resin was not evaluated as "A", and the resin layer was slightly left in the metal-filled fine structure. The upper one was evaluated as "B", and the resin layer remaining on almost the entire surface of the metal-filled microstructure was evaluated as "C". Further, in Comparative Example 1, since the substrate removal step was not performed, the separation property was not evaluated, and "-" was expressed in Table 1 below.

<Two-sided crimpability> A test element group (TEG) wafer (daisy chain pattern) and an interposer manufactured by WALTS were prepared, and the components were placed on the wafer. The alignment of the chip holder is adjusted in advance. After the alignment adjustment, the metal-filled fine structures produced by the interposing on the Cu column side of the interposer provided on the lower side (when the resin layer is provided, the metal-filled fine structure after removing the resin layer) The mixture was heated and pressure-bonded at 250 ° C, 1 minute, and 6 MPa using a room temperature bonding apparatus (WP-100, manufactured by PMT Corporation) to bond. For the bonded samples, a bond tester (DAGE 4000, manufactured by Dage Co., Ltd.) was used, and a load was applied to the TEG wafer to measure the peel strength. As a result, the case where the peeling strength was 20 N or more was evaluated as "S", the case of 15 N or more and less than 20 N was evaluated as "A", and the case of 10 N or more and less than 15 N was evaluated as "B", 2 N. The case where the above is less than 10 N is evaluated as "C", and the case where it is less than 2 N is evaluated as "D".

[Table 1] * The thickness of the metal-filled microstructure is the thickness excluding the resin layer and the substrate.

From the results shown in Table 1, when the barrier layer removal step was carried out using an aqueous alkali solution containing no metal M1 having a hydrogen overvoltage higher than aluminum, the metal filled in the micropores was filled with or without the substrate removal step. The in-plane uniformity was poor (Comparative Example 1 and Comparative Example 2).

On the other hand, when the barrier layer removal step is performed using an aqueous alkali solution containing a metal having a hydrogen overvoltage higher than aluminum, it is known that the in-plane uniformity of the metal filled in the micropores is good (Example 1 to Example 22). In particular, from the comparison of Examples 1 to 4, if the metal M1 used in the barrier layer removing step is a metal having a higher ionization tendency than the metal M2 used in the metal filling step, the metal filled in the micropores is filled. The in-plane uniformity becomes better. Further, from the comparison between Example 4 and Examples 5 to 9, it is found that when the resin layer is provided, the conveyability is improved.

1‧‧‧Aluminum substrate
2‧‧‧Micropores
3‧‧‧Barrier layer
4‧‧‧Anodized film
5a‧‧‧Metal M1
5b‧‧‧Metal M2
5‧‧‧Metal
7‧‧‧ resin layer
10, 20‧‧‧Metal filled fine structure
21‧‧‧Volume core
30‧‧‧Rubber roll

1A is a schematic cross-sectional view showing an example of a method for producing a metal-filled microstructure according to the present invention (a first aspect), and is a schematic cross-sectional view showing an aluminum substrate subjected to anodization. 1B is a schematic cross-sectional view showing a state after the anodizing treatment step in a schematic cross-sectional view showing an example (first aspect) of a method for producing a metal-filled microstructure according to the present invention. 1C is a schematic cross-sectional view showing a state after the step of removing the barrier layer in a schematic cross-sectional view showing an example (first aspect) of the method for producing the metal-filled microstructure according to the present invention. 1D is a schematic cross-sectional view showing a state after a metal filling step in a schematic cross-sectional view showing an example (first aspect) of a method for producing a metal-filled microstructure according to the present invention. 1E is a schematic cross-sectional view showing a state after a substrate removal step in a schematic cross-sectional view showing an example (first aspect) of a method for producing a metal-filled microstructure according to the present invention. 2A is a schematic cross-sectional view showing another example (second aspect) of the method for producing a metal-filled microstructure according to the present invention, and shows an aluminum substrate subjected to anodization. 2B is a schematic cross-sectional view showing a state after the anodizing treatment step in a schematic cross-sectional view showing an example (second aspect) of the method for producing the metal-filled microstructure according to the present invention. 2C is a schematic cross-sectional view showing a state after the step of removing the barrier layer in a schematic cross-sectional view showing an example (second aspect) of the method for producing the metal-filled microstructure according to the present invention. 2D is a schematic cross-sectional view showing a state after the metal filling step in a schematic cross-sectional view showing an example (second aspect) of the method for producing the metal-filled microstructure according to the present invention. 2E is a schematic cross-sectional view showing a state after the surface metal protruding step in a schematic cross-sectional view showing an example (second aspect) of the method for producing the metal-filled microstructure according to the present invention. 2F is a schematic cross-sectional view showing a state after the substrate removal step in a schematic cross-sectional view showing an example (second aspect) of the method for producing the metal-filled microstructure according to the present invention. 2G is a schematic cross-sectional view showing a state after the back metal protruding step in a schematic cross-sectional view showing an example (second aspect) of the method for producing the metal-filled microstructure according to the present invention. 3A is a schematic cross-sectional view showing another example (third aspect) of the method for producing a metal-filled microstructure according to the present invention, and shows an aluminum substrate subjected to anodization. 3B is a schematic cross-sectional view showing a state after the anodizing treatment step in a schematic cross-sectional view showing an example (third aspect) of the method for producing the metal-filled microstructure according to the present invention. 3C is a schematic cross-sectional view showing a state after the step of removing the barrier layer in a schematic cross-sectional view showing an example (third aspect) of the method for producing the metal-filled microstructure according to the present invention. 3D is a schematic cross-sectional view showing a state after the metal filling step in a schematic cross-sectional view for explaining an example (third aspect) of the method for producing the metal-filled microstructure according to the present invention. 3E is a schematic cross-sectional view showing a state after the resin layer forming step in a schematic cross-sectional view showing an example (third aspect) of the method for producing the metal-filled microstructure according to the present invention. 3F is a schematic cross-sectional view showing a state after the substrate removal step in the schematic cross-sectional view for explaining an example (third aspect) of the method for producing the metal-filled microstructure according to the present invention. FIG. 4 is a schematic view for explaining an example of a supply form of the metal-filled fine structure produced by the method for producing a metal-filled microstructure according to the present invention. Fig. 5A is a schematic view for explaining a test body used for evaluation of conveyance. Fig. 5B is a schematic view for explaining a test body used for evaluation of conveyability.

1‧‧‧Aluminum substrate

2‧‧‧Micropores

3‧‧‧Barrier layer

4‧‧‧Anodized film

5a‧‧‧Metal M1

5b‧‧‧Metal M2

5‧‧‧Metal

10‧‧‧Metal filled fine structure

Claims (13)

A method for manufacturing a metal-filled microstructure includes the following steps: an anodizing treatment step of anodizing a surface of one side of an aluminum substrate to form an anodized film on a surface of one side of the aluminum substrate, wherein The anodic oxide film has micropores present in a thickness direction and a barrier layer present at a bottom of the micropores; a barrier layer removing step, after the anodizing treatment step, using a hydrogen overvoltage higher than aluminum An alkali aqueous solution of the metal M1 removes the barrier layer of the anodized film; a metal filling step, after the barrier layer removing step, performing an electrolytic plating process to fill the inside of the micropore with a metal M2 And a substrate removing step of removing the aluminum substrate to obtain a metal-filled microstructure after the metal filling step. The method for producing a metal-filled microstructure according to claim 1, wherein the metal M1 used in the barrier layer removal step has a higher ionization tendency than that used in the metal filling step. Metal of metal M2. The method for producing a metal-filled microstructure according to claim 1 or 2, wherein after the metal filling step and before the substrate removing step, a surface metal protruding step is included, the anode is The surface of the oxide film on the side where the aluminum substrate is not provided is partially removed in the thickness direction, so that the metal M2 filled in the metal filling step is more prominent than the surface of the anodized film. The method for producing a metal-filled microstructure according to claim 1 or 2, wherein after the substrate removing step, including a back metal protruding step, the anodized film is provided with the aluminum The surface on the side of the substrate is partially removed in the thickness direction, so that the metal M2 filled in the metal filling step is more prominent than the surface of the anodized film. The method for producing a metal-filled microstructure according to claim 3, wherein after the substrate removing step, a back metal protruding step is included, and the side of the anodized film on which the aluminum substrate is provided The surface is partially removed in the thickness direction such that the metal M2 filled in the metal filling step is more prominent than the surface of the anodized film. The method for producing a metal-filled microstructure according to claim 3, wherein the surface metal protruding step is a step of causing the metal M2 to protrude from the surface of the anodized film by 10 nm to 1000 nm. The method for producing a metal-filled microstructure according to claim 4, wherein the back metal protrusion step is a step of causing the metal M2 to protrude from the surface of the anodized film by 10 nm to 1000 nm. The method for producing a metal-filled microstructure according to claim 5, wherein the surface metal protruding step and the back metal protruding step are at least one step of making the metal M2 smaller than the anodized film. The surface protrudes from 10 nm to 1000 nm. The method for producing a metal-filled microstructure according to claim 1 or 2, wherein after the metal filling step and before the substrate removing step, a resin layer forming step is included in the anode A resin layer is provided on the surface of the oxide film on the side where the aluminum substrate is not provided. The method for producing a metal-filled microstructure according to claim 9, wherein the resin layer is a peelable adhesive layer-attached film. The method for producing a metal-filled microstructure according to claim 9, wherein the resin layer is a film having an adhesive layer which is weakened by adhesion by heat treatment or ultraviolet exposure treatment and which is peelable. . The method for producing a metal-filled microstructure according to claim 9, wherein the anodized film formed by the anodizing treatment step has an average thickness of 30 μm or less. The method for producing a metal-filled microstructure according to claim 9, wherein after the substrate removing step, the winding step is performed, and the metal-filled microstructure is wound up in a state having the resin layer. Rolled.